08/15/2008. Remarks by Ray Watkins: "This helicopter was a pet project for Arthur Young to evaluate the co-axial rotor system following the flight of similar machines by Stanley Hiller (XH-44 in 1944) and Horace Pentecost (Hoppi-Copter 101 in 1946). The machine soon developed problems with the transmission and as it wasn't liked by Lawrence Bell it never went into production."